1980 Volume 37 Issue 10 Pages 671-676
Poly (ethylene glycol) (PEG) containing amino groups at the ends (NH2-PEG) was prepared by amination of PEG-4000 (average of Molecular weight 3000) with ethyleneimine-boron trifluoride etherate. Water-soluble Mo2O2 (μ-S) 2 (Cys-NH-PEG) 2 was synthesized from Mo2O2 (μ-S) 22+ ion and the Cys-NH-PEG obtained by the reaction of the NH2-PEG with N, S-ciitrityl-L-cysteine. Chelation of S-N ligands to a molybdenum atom was confirmed by studies with IR (930 cm-1 Mo=O, 470 cm-1 Mo-Sb), visible, and CD spectra of the complex in water or in polar organic solvents, such as THF. A Mo (V) complex was also synthesized from Ala-Cys-NH-PEG, prepared with the procedure of Mutter's peptide synthesis from the NH2-PEG and t-butyloxycarbonyl amino acids, and Mo2O2 (μ-S) 22+ ion. The IR, visible, and CD spectra of the complex were compared to those of the simple model complex. High solubility in water due to the hydrophilicity of the PEG groups makes these new polymer complexes useful as metalloenzyme models.
